Bluefin.Exception.Dynamic

Dynamic exceptions

This is the vanilla exception mechanism from IO. Use this module to handle exceptions from external (non-bluefin) APIs.

Another motivation is to serve as a principled (experimental) framework for resource management with bracket.

The core Bluefin API exposes a bracket in Bluefin.Eff which (intentionally) weakens the scoping of scoped exceptions in Bluefin.Exception.

This module is an experiment for a world where

• scoped exceptions are truly scoped (unlike Bluefin.Exception);
• the capability to catch and throw dynamic exceptions is explicit (unlike bracket in Bluefin.Eff).

Documentation

data DynExn (ex :: Effects)

Capability to catch and throw dynamic exceptions.

runDynExn :: (forall ex. DynExn ex -> Eff ex a) -> a

Run a computation with only access to dynamic exceptions.

ioeToDynExn :: IOE io -> DynExn io

Refine an IOE capability to a DynExn.

throw :: (Exception e, ex :> es) => DynExn ex -> e -> Eff es a

Throw an exception.

catch :: (Exception e, ex :> es) => DynExn ex -> Eff es a -> (e -> Eff es a) -> Eff es a

Catch an exception.

bracket :: ex :> es => DynExn ex -> Eff es a -> (a -> Eff es ()) -> (a -> Eff es b) -> Eff es b

bracket ex acquire release run: acquire a resource, run a computation depending on it, and finally relase the resource even if run threw an exception.

finally :: ex :> es => DynExn ex -> Eff es a -> Eff es () -> Eff es a

finally ex run cleanup: run a computation, then cleanup even if run threw an exception.

onException :: ex :> es => DynExn ex -> Eff es a -> Eff es () -> Eff es a

onException ex run cleanup: run a computation, and if an exception is thrown, cleanup, then rethrow the exception.

throwIO :: (Exception e, io :> es) => IOE io -> e -> Eff es a

throw with an IOE capability.

catchIO :: (Exception e, io :> es) => IOE io -> Eff es a -> (e -> Eff es a) -> Eff es a

catch with an IOE capability.